1. Field of the Invention
The present invention relates to a surface wave excitation plasma generator for generating surface wave excitation plasma by introducing microwave from a microwave generator, and a surface wave excitation plasma processing apparatus for performing chemical vapor deposition (CVD) or etching by utilizing the surface wave excitation plasma.
2. Description of Related Art
Surface wave plasma (SWP) is generated through the following ways. A microwave propagating in a microwave waveguide is introduced into a dielectric member through a slot antenna, and the plasma is excited by a surface wave generated on the surface of the dielectric member due to the microwave power to generate surface wave excitation plasma. For this kind of microwave waveguides, annular waveguides without ends but having a plurality of slot antennas disposed on the bottom plate thereof are already known in the art (for example, with reference to Patent Document 1).
Patent Document 1: Japanese Patent Laid-Open Publication No. H05-345982 (Page 2, FIGS. 6 and 9).
Since the annular waveguide without ends disclosed in Patent Document 1 includes no end parts, the microwave propagating in the waveguide is disturbed; thus, a stable standing wave cannot be formed, and the phase of the standing wave and the relative positions between slot antennas become unfixed, so that the microwave power is focused on a specific slot antenna. Accordingly, the surface wave excitation plasma has a problem of low yield.